The perovskite solar cells now compete with traditional silicon solar cells with an efficiency of 26%. For the 10 years, organic-inorganic halide perovskite solar cells have seen growth in photovoltaic industry due to a number of positive qualities, such as high electron and hole mobility, broad and tunable band gap, defect tolerance, ease of fabrication, availability of raw materials, and well-understood synthesis techniques. The presence of lead lowers the market values of perovskite solar cells due to its toxicity and danger to the environment. Recently, researchers are focusing on lead free perovskite and tin (Sn) based perovskites have shown promising results as a replacement for lead, with efficiency and stability increasing rapidly.Among the lead free perovskites, Cs₂SnI₆ an all inorganic, lead free and air stable material has received more attention as an absorber layer. It is a defective variant the three-dimensional cubic perovskite material - CsSnI₃. The cesium atoms in regular 12-fold coordination fill the sites between (SnX₆) octahedral. It has been suggested that the Sn⁴⁺ state and the presence of a potent Sn-I covalent bond are responsible for Cs₂SnI₆'s natural resistance to oxidation and great stability. The maximum efficiency obtained so far is 2.02%; it is a prospective material that can be employed for developing more efficient and stable perovskite solar cells.